Twitter's Big Battle Is Indifference

Social Network Leaves Many Individual Users Cold

Twitter Inc.'s pitch to people like Christine Harsono isn't hitting its target.

The 21-year-old Los Angeles waitress has yet to give into years of nudging by Twitter to sign up. A Facebook Inc. member since 2008, she says she sees no reason to tweet, even as her favorite TV shows, such as "The Voice," urge her to join the Twitter...